Promo code for 1 item, 1 category, 1 brand or otherwise not limited to all or nothing

I'd like more flexibility with website promo codes - ie to have the ability to add a promo code for a specific SKU/item, a category, a brand, a price range (over or under or between a $ amount, etc etc.).  We have many different types of products & we'd like to have our website allow promo codes based on various criteria.  One example would be 5% off items under $100, 10% off items between $100 & $500, etc etc.   Or just $x or x% off anything in y category, or y brand, or sku's a, b c.  Or anything with "ABC" in the title.

Thanks!

- Mac